1. Field of the Invention
The present invention relates to the field of medical instrumentation, specifically to the use of smart technology within miniature remote devices for the inspection, diagnosis, and treatment of internal organs of living organisms.
2. Description of Related Technology
Endoscopic and colonoscopic techniques are commonly used to inspect the accessible upper and lower portions, respectively, of the human gastrointestinal tract. A traditional endoscopic inspection of a human being (an example of which is the “EGD”) requires the patient to be partially or completely sedated while a long, thin, tubular probe is introduced into the esophagus, routed through the stomach, and ultimately into the upper portion of the small intestine (duodenum). This tubular probe typically contains a self-illuminating fiber optic cable and viewing device to allow visual inspection of tissue in the vicinity of the probe tip. See, for example, U.S. Pat. No. 3,901,220, “Endoscopes” issued Aug. 26. 1975. However, due to the tortuous path, fragility, small diameter, and length of the digestive tract, prior art endoscopic inspection such as the aforementioned EGD is limited to only the stomach and upper portions of the small intestine. See FIG. 1.
Similarly, traditional colonoscopic examination utilizes a thin, tubular fiber optic probe inserted into the large intestine (colon) via the rectum. Even the most penetrating colonoscopic inspections are limited to the colon and the terminal portion of the small intestine (ileum), due again primarily to the tortuosity and fragility of the large intestine and ileum. While a substantial number of diseases and conditions afflict the stomach. duodenum, colon, and ileum, several others may occur within the remaining, inaccessible portions of the gastrointestinal tract including the jejunum of the small intestine.
Both endoscopic and colonoscopic inspections further run a small but significant risk of physical damage to the patient, such as perforation of the duodenum or ileum, especially where disease has progressed to an advanced stage and the surrounding tissue has weakened or degenerated.
Alternatively, non-invasive diagnostic techniques such as X-ray inspection (e.g., so-called “upper-GI” and “lower-GI” series), which involves introducing barium or other contrast agents into the patient, are useful in identifying gross abnormalities, but require careful interpretation and are susceptible to misdiagnosis, shielding effects, and a plethora of other potential pitfalls. Furthermore, such techniques expose the patient to significant doses of ionizing X-ray radiation which ultimately may be deleterious to the patients health.
The somewhat related technique of X-ray computed axial tomography (CAT) scanning provides information about the general condition of an individual's intestinal tract and internal organs, yet does not possess the necessary resolution to facilitate diagnosis of many types of conditions. It also suffers from the drawback of exposing the patient to substantial quantities of X-ray radiation. CAT scans of the GI tract also may require the use of ingested and/or intravenous contrast agents, the latter notably having a small but non-zero incidence of patient mortality. Furthermore, certain patients may not be given such contrast agents due to allergies or other pre-existing medical conditions, thereby substantially reducing the efficacy of the CAT scan as a diagnostic technique for these patients.
Magnetic resonance imaging (MRI) techniques, well known in the medical diagnostic arts, have certain benefits as compared to the aforementioned CAT scan, yet also suffer from limitations relating to resolution and interpretation of the resulting images, and in certain instances the required use of “contrast” agents. More recently, enhanced MRI techniques are being used to aid in the diagnosis and treatment of Crohn's disease, yet even these enhanced techniques suffer from limitations relating to resolution, especially when the disease has not progressed to more advanced stages.
Another related and well known medical diagnostic technology is that of autofluorescence endoscopy. Simply stated, autofluorescence endoscopy uses a light source having specific characteristics (typically a coherent source such as a laser) to illuminate a portion of tissue under examination; the incident light excites electrons within the atoms of the tissue which ultimately produce a quantum transition therein resulting in an emission of electromagnetic radiation (fluorescence) from the tissue at one or more wavelengths. Additionally, so-called “remitted” energy, which is incident or excitation energy reflected or scattered from the tissue under analysis, is also produced. The fundamental principle behind the autofluorescence technique is that diseased or cancerous tissue has a different autofluorescence (and remitted light) spectrum than that associated with healthy tissue of similar composition; see FIG. 2. Generally speaking, diseased tissue autofluoresces to a lesser degree at a given wavelength under the same incident excitation radiation than healthy tissue. See, for example, U.S. Pat. No. 4,981,138, “Endoscopic Fiberoptic Fluorescence Spectrometer” issued Jan. 1, 1991. Unfortunately, however, the applicability of autofluorescence techniques has traditionally been limited to external areas of the body, or those accessible by endoscopic probe, thereby making this technique ineffective for diagnosing diseases of the central portion (jejunum) of the small intestine. See also U.S. Pat. No. 5,827,190, “Endoscope Having an Integrated CCD Sensor”.
In summary, endoscopic inspection is arguably the most efficient and effective prior art method of diagnosing conditions of the intestinal tract, especially those of a more chronic and insidious nature. However, due to its limited reach, endoscopic inspection is not an option for diagnosing or treating the central portions of the digestive tract, specifically the central region of the small intestine.
Based on the foregoing, it would be highly desirable to provide an apparatus and method by which treatment could be rendered remotely to various portions of the intestinal tract. More specifically, it would be highly desirable to provide an apparatus and method by which visual inspection of all portions of the interior of the digestive tract including the small intestine could be made without invasive surgery or other extraordinary and potentially deleterious means. Furthermore, it would be desirable to provide an apparatus and method by which autofluorescence analysis of the interior of the digestive tract could be performed remotely.